Obtaining real-time 3D co-ordinates of a moving object has many applications such as gaming [1], robotics and human-computer interaction applications [2-4], industrial applications etc. Various technologies have been investigated for and used in these applications, including sensing via wire-interfaces [2], ultrasound, and laser interferometry. However a simple and low cost solution that can provide enough precision and flexibility has not been available. Recent proliferation of low-cost inertial sensors has not addressed the problem of position tracking Cassinelli et al demonstrated a scanning mirror-based tracking solution [3-4]; however their system does not solve the problem of object searching/selecting and does not have adequate depth (Z-axis) measurements.
In addition it is often desirable to obtain good resolution on the position of the object when it is close to the tracking system. Unfortunately, many existing tracking systems tend to lose resolution when the object is close in.
Many video-based tracking systems utilize charge-coupled device (CCD) arrays to obtain position information from an image of the object that is being tracked. Unfortunately, the image is two-dimensional and additional information is usually needed in order to derive three-dimensional position information. In addition, a CCD typically has a limited field of view. Furthermore, there is a large cost differential associated with increasing the resolution of CCD array.
It is within this context that embodiments of the present invention arise.